[math] allow TH2::FillRandom xygaus

Fixes #20719

Author: ferdymercury

core/base/src/TROOT.cxx

@@ -1607,7 +1607,7 @@ TObject *TROOT::GetFunction(const char *name) const
    // and restart after this thread has finished the initialization (i.e. a rare case),
    // the only penalty we pay is a spurious 2nd lookup for an unknown function.
    [[maybe_unused]] static const auto _res = []() {
-      gROOT->ProcessLine("TF1::InitStandardFunctions();");
+      gROOT->ProcessLine("TF1::InitStandardFunctions(); TF2::InitStandardFunctions(); TF3::InitStandardFunctions();");
       isInited = true;
       return true;
    }();

gui/fitpanel/src/CommonDefs.h

@@ -11,7 +11,8 @@ enum EFitPanel {
    kFP_CHEB0,  kFP_CHEB1,  kFP_CHEB2,  kFP_CHEB3,  kFP_CHEB4,  kFP_CHEB5,
    kFP_CHEB6,  kFP_CHEB7,  kFP_CHEB8,  kFP_CHEB9,
    kFP_XYGAUS, kFP_BIGAUS, kFP_XYEXP, kFP_XYLAN, kFP_XYLANN,
-// Above here -> All editable formulaes!
+   kFP_XYZGAUS,
+   // Above here -> All editable formulaes!
    kFP_USER,
    kFP_NONE,  kFP_ADD,   kFP_NORMADD,   kFP_CONV,  kFP_FILE,  kFP_PARS,  kFP_RBUST, kFP_EMPW1,
    kFP_INTEG, kFP_IMERR, kFP_USERG, kFP_ADDLS, kFP_ALLW1, kFP_IFITR, kFP_NOCHI,

gui/fitpanel/src/TFitEditor.cxx

@@ -1664,11 +1664,21 @@ void TFitEditor::FillFunctionList(Int_t)
 
       // Select Gaus2D by default
       fFuncList->Select(kFP_XYGAUS);
+   } else if (fTypeFit->GetSelected() == kFP_PRED3D && fDim == 3) {
+      fFuncList->AddEntry("xyzgaus", kFP_XYZGAUS);
+
+      // Need to be setted this way, otherwise when the functions
+      // are removed, the list doesn't show them.x
+      TGListBox *lb = fFuncList->GetListBox();
+      lb->Resize(lb->GetWidth(), 200);
+
+      // Select Gaus3D by default
+      fFuncList->Select(kFP_XYZGAUS);
    }
    // Case for user defined functions. References to these functions
    // are kept by the fitpanel, so the information is gathered from
    // there.
-   else if ( fTypeFit->GetSelected() == kFP_UFUNC ) {
+   else if (fTypeFit->GetSelected() == kFP_UFUNC) {
       Int_t newid = kFP_ALTFUNC;
 
       // Add system functions
@@ -1701,7 +1711,7 @@ void TFitEditor::FillFunctionList(Int_t)
       }
    }
    // Case for previously used functions.
-   else if ( fTypeFit->GetSelected() == kFP_PREVFIT ) {
+   else if (fTypeFit->GetSelected() == kFP_PREVFIT) {
       Int_t newid = kFP_ALTFUNC;
 
       // Look only for those functions used in the selected object

gui/fitpanelv7/src/RFitPanel.cxx

@@ -284,6 +284,8 @@ void RFitPanel::UpdateFunctionsList()
                     {"cheb0"}, {"cheb1"}, {"cheb2"}, {"cheb3"}, {"cheb4"}, {"cheb5"}, {"cheb6"}, {"cheb7"}, {"cheb8"}, {"cheb9"} };
    } else if (m.fDim == 2) {
       m.fFuncList = { {"xygaus"}, {"bigaus"}, {"xyexpo"}, {"xylandau"}, {"xylandaun"} };
+   } else if (m.fDim == 3) {
+      m.fFuncList = {{"xyzgaus"}};
    }
 
    for (auto &func : fSystemFuncs) {

hist/hist/inc/TF2.h

@@ -111,6 +111,7 @@ class TF2 : public TF1 {
    virtual Double_t GetMaximum(Double_t *x ) const;
    virtual Double_t GetYmin() const {return fYmin;}
    virtual Double_t GetYmax() const {return fYmax;}
+   static void InitStandardFunctions();
    using TF1::Integral;
    virtual Double_t Integral(Double_t ax, Double_t bx, Double_t ay, Double_t by, Double_t epsrel=1.e-6);
    Bool_t   IsInside(const Double_t *x) const override;

hist/hist/inc/TF3.h

@@ -97,6 +97,7 @@ class TF3 : public TF2 {
    Double_t GetSave(const Double_t *x) override;
    virtual Double_t GetZmin() const {return fZmin;}
    virtual Double_t GetZmax() const {return fZmax;}
+   static void InitStandardFunctions();
    using TF2::Integral;
    virtual Double_t Integral(Double_t ax, Double_t bx, Double_t ay, Double_t by, Double_t az, Double_t bz, Double_t epsrel=1.e-6);
    Bool_t   IsInside(const Double_t *x) const override;

hist/hist/src/TF1.cxx

@@ -2550,6 +2550,7 @@ void TF1::InitStandardFunctions()
 
    }
 }
+
 ////////////////////////////////////////////////////////////////////////////////
 /// IntegralOneDim or analytical integral
 

hist/hist/src/TF2.cxx

@@ -663,6 +663,27 @@ Double_t TF2::GetSave(const Double_t *xx)
    return z;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// Create the basic function objects
+
+void TF2::InitStandardFunctions()
+{
+   TF2 *f2;
+   R__LOCKGUARD(gROOTMutex);
+   if (!gROOT->GetListOfFunctions()->FindObject("xygaus")) {
+      f2 = new TF2("xygaus", "xygaus", -1, 1, -1, 1);
+      f2->SetParameters(1, 0, 1, 0, 1);
+      f2 = new TF2("bigaus", "bigaus", -1, 1, -1, 1);
+      f2->SetParameters(1, 0, 1, 0, 1, 0);
+      f2 = new TF2("xyexpo", "xyexpo", -1, 1, -1, 1);
+      f2->SetParameters(1, 0, 1, 1, 0, 1);
+      f2 = new TF2("xylandau", "xylandau", -1, 1, -1, 1);
+      f2->SetParameters(1, 0, 1, 1, 0, 1);
+      f2 = new TF2("xylandaun", "xylandaun", -1, 1, -1, 1);
+      f2->SetParameters(1, 0, 1, 1, 0, 1);
+   }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// Return Integral of a 2d function in range [ax,bx],[ay,by]
 /// with desired relative accuracy (defined by eps)

hist/hist/src/TF3.cxx

@@ -479,6 +479,19 @@ Double_t TF3::GetSave(const Double_t *xx)
    return r;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// Create the basic function objects
+
+void TF3::InitStandardFunctions()
+{
+   TF3 *f3;
+   R__LOCKGUARD(gROOTMutex);
+   if (!gROOT->GetListOfFunctions()->FindObject("xyzgaus")) {
+      f3 = new TF3("xyzgaus", "xyzgaus", -1, 1, -1, 1, -1, 1);
+      f3->SetParameters(1, 0, 1, 0, 1, 0, 1);
+   }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// Return Integral of a 3d function in range [ax,bx],[ay,by],[az,bz]
 /// with a desired relative accuracy.

hist/hist/src/TFormula.cxx

@@ -2548,7 +2548,7 @@ void TFormula::FillParametrizedFunctions(map<pair<TString, Int_t>, pair<TString,
    // 3-dimensional function
    functions.insert(
       make_pair(make_pair("gaus", 3), make_pair("[0]*exp(-0.5*(({V0}-[1])/[2])^2 - 0.5*(({V1}-[3])/[4])^2 - 0.5*(({V2}-[5])/[6])^2)", "")));
-   // gaussian with correlations
+   // 2-d gaussian with correlations
    functions.insert(
       make_pair(make_pair("bigaus", 2), make_pair("[0]*ROOT::Math::bigaussian_pdf({V0},{V1},[2],[4],[5],[1],[3])",
                                                   "[0]*ROOT::Math::bigaussian_pdf({V0},{V1},[2],[4],[5],[1],[3])")));